The present invention relates to a circuit configuration for a brake system with anti-lock control and/or traction slip control. The brake system includes wheel sensors for generating electric signals representing the wheel rotational behavior, and the circuit configuration includes circuits for forming a vehicle reference speed, for selecting sensor signals, for identifying cornering and for generating braking pressure control signals. The rotational behavior of the wheels of each vehicle side is determined separately in a first step, and the measured values of each vehicle side are then compared in a second step.
Similar circuit configurations for anti-lock brake systems with circuits for cornering identification are known. According to German patent application 34 13 738, the wheel rotational behavior is measured by wheel sensors, the slip is determined by comparing the measured values with a vehicle reference speed, and the slip sum is formed individually for each vehicle side. Finally, the difference of the slip sums of both vehicle sides is ascertained, and the selection criteria (select-low, etc.) dictating the influence of the individual wheels on the control is varied when the difference of the slip sums exceeds a limit value. In this manner, the control is adapted to the different vehicle behavior while driving straight forward, or while cornering.
German patent application 21 19 590 teaches an anti-lock control system which measures the transverse acceleration of the vehicle, such as by virtue of a mercury switch, for cornering identification. In this system, the wheels of an axle are controlled according to the select-high principle in the normal case, and after the cornering identification there is a change-over to select-low. Furthermore, systems are known which, for cornering identification, employ a steering-angle signalling device in the form of a switch which is operated mechanically upon steering movement. The output signal of this device influences the anti-lock control system by modifying it in view of the changed vehicle behavior during cornering.
It is an object of the present invention to provide a circuit configuration which, from only the information supplied by the existing wheel sensors, derives a cornering-identification signal and which provides a precisely responsive adaptation of the control to different driving and road situations.